The present invention relates to a spacer which is located between upper and lower molars and enables to keep a predetermined space, for adjusting occlusion, and a mouthpiece which are mounted on teeth located in an upper or a lower jaw by using a spacer.
When a denture or a mouthpiece available for athletic sports is produced, in many cases a wax plate having a thickness of 3 to 4 mm (which is called a bite wax) has hitherto been used. The bite wax is bitten in a state, wherein the bite wax is softened by heating, by a patient or the like so that a dell is formed on both sides thereof. Thereby, a mutual relationship of the upper and the lower jaw in such a state that the elevation of several mm as to the occlusion is obtained. On the other hand, a gnathic model, which is made from gypsum, of patients and the like is formed. Thereafter, the model is inserted into an articulator in such a manner that the bite wax is interposed between the upper and the lower molar parts the model. Thereby, the mutual relationship, wherein the elevation having a predetermined space is performed, is reproduced. Thereby, producing the denture or the mouthpiece is performed.
When the elevation of the position of occlusion is performed by using the bite wax as mentioned hereinbefore, the space of the elevation varies in accordance with occlusion pressure (high pressure or low pressure). For this reason, considerable maturity is required even for a dentist in order to obtain a predetermined value of elevation. As is often the case, the value of elevation is still thinner or thicker than the desired value of elevation. Then, it is quite often that the patient bites off the bite wax.
With respect to the mouthpiece which is put on sale (or available), a player (or athlete) buys the bite wax in a shop, and thereafter soaks it in hot water. Thereby, the bite wax is softened. Then, the mouthpiece is shaped by biting between the upper and the lower molars, and pressure is applied to the mouthpiece from tongue-side and cheek-side. However, in the above case, it is very difficult to obtain an optimum value, which is set beforehand, of the elevation of the position of occlusion. It depends upon a temperature of the hot water and soaking time that material of the mouthpiece softens. Further, there is a difference between individuals in the occlusion pressure. For this reason, it often happens that the space of elevation is thicker or thinner than the standard value and the above-mentioned problems arise.
As this kind of the mouthpiece, the mouthpiece made of a thermoplastic resin which is softened at a temperature being not more than 100.degree. C. having such a construction as to be inserted by the core member such as a weaving cloth is known (Japanese Unexamined Patent Publication No. 60672/1990).
Further, the above Japanese Publication discloses a mouthpiece wherein softened resin is prevented from dropping down by the core member when the mouthpiece is heated. The above Japanese Publication does not disclose such a technique that the position of occlusion is elevated with a certain space between the upper and the lower molar by means of the core member. Actually, weaving cloth or woven fabric is so thin that the elevation of the position of occlusion cannot be performed by several nun. Then, if the weaving cloth and the like is made to be thick so as to have a thickness of several mm, restoring force against deformation is so big as to be ignored since elastic modulus of the weaving cloth is higher than that of the above thermoplastic resin. As a result, the mouthpiece is in danger of deforming before the mouthpiece is cured by cooling after shaping.
The object of the present invention is to delete the above problems and to provide a spacer and a mouthpiece, wherein an elevation of position of occlusion with having a predetermined space between the upper and the lower molars, can be easily and accurately performed by even a person who is not mature.